Sun valve



April 16, 1935. E. H. PENDLETON l997,593

SUN VALVE Filed April 10, 1933 PIIE' E WT 5 INVENTOR.

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Patented Apr. 16, 1935 SUN VALVE Edwin H. Pendleton, Venice, Calif., assignor to Econolite Corporation, Los Angeles, Calif, a corporation of California Application April '10, 1933, Serial No. 665,310

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My invention relates to means for affecting an electrical circuit or other operating instrumentality in accordance with sun radiation, and is especially'useful in conjunction with signal circults such as shown in my co-pending application entitled Flasher, filed April 1933, with Serial Number 665,311. 7 An object of my invention is to provide means responsive to sun radiation for controlling an electrical circuit or comparable operating means. i A further object of my invention is t'otp'rovide an extremely simple mechanism "responsive to sun radiation.

Another object of my invention is to provide a sun valve which is compensated for atmospheric temperature variations.

The foregoing and other objects are attained in the embodiment of the invention as shown in the drawing, in which- Figure l is a cross-section on a vertical, longitudinal plane of a sun valve constructed in accordance with my invention.

Figure 2 is a cross-section the plane of which is indicated by the line 2-2 of Figure l.

Figure 3 is a cross-section the plane of which is indicated by the line 3-3 of Figure 1.

In its preferred form the sun valve of my invention comprises a thermo-responsive element carrying a contact included in an electrical circuit, the thermo-responsive element being subjected to a relatively large amount of sun radiation, combined with a second thermo-responsive element controlling another contact in the electrical circuit, the second thermo-responsive element being subject to a lesser amount of sun radiation.

Although the sun valve of my invention can be incorporated in various different forms and is susceptible to use in a multiplicity of different environments, I have shown it herein in one successful form which includes a chamber 6 affording a shelter from direct rays of the sun, and a generally cylindrical side-wall 1 provided with ventilating apertures 8 and a top wall 9. The side wall 1 can be provided with one or more brackets II for affixing the sun valve to a support, and likewise incorporates a mounting block l2 preferably of insulating material.

Adjoining the chamber 6 is a chamber l3 preferably made up of a top wall I 4 and a cylindrical side wall l6 usually fabricated of quartz, glass, or other material permeable by sun rays. The wall l6 terminates in a threaded neck I! interengaging a comparably threaded collar I8 joined to the impermeable side wall 1. Situated within the chamber I3 is a first thermo-respo'nsive element l9 which includes an arm 2! pivotally mounted on a spindle 22 carried between the arms of a bracket 23 secured. to the wall 9 and freely rotatable with respect thereto. l

A bimetallic brother thermostatic strip 24 is coiled into a spiral and has one end affixed to the spindle 22 and its opposite end afiixed by a fastening 26fto the bracket 23. A conductor 21, forming part of an electrical circuit, is secured to the bracket, so that electricity flowing through thelead Z'I'passes through the'strip '24 andthe arm 2| to a first contact 29. Co-operating with the contact 29 is a comparable contact 3| mounted on an arm 32 included in a second thermo-responsive element generally designated 33. The arm 32 is mounted on a spindle 34 carried in a bracket 36 secured to a plate 31 fastened to the block l2. A thermostatic strip 39, preferably of bimetallic material, is arranged with one end fastened to the arm 32 and its other end secured to a binding post 4|. An electrical lead 42 included in the electrical circuit conducts current from the contact 3! through the arm 32 and the spiral strip 39 to the lead 42. Thus, when the contacts 29 and 3! are in abutment the electrical circuit is closed, while when the contacts are separated the circuit is open.

If the thermo-responsive elements 24 and 39 were responsive in substantially equal amounts to given temperature fluctuations, they would remain in abutment although travelling in arcuate paths throughout their range of movement, and therefore maintain the circuit closed. However,

in accordance with my invention, I provide means for rendering the contacts 29 and 3| differentially movable in response to varying amounts of sun radiation affecting each of the bimetallic strips 24 and 39.

To this end the element 2| is preferably enclosed in a housing 43 which preferably is of metal and which in connection with the wall 9 completely encloses the responsive element. The material of the housing 43 is preferably black or treated with black material, to be highly absorptive to sun rays, whereas the walls l4 and E3 of the chamber I3 prevent air currents from reducing the temperature established within the housing 43 by the relatively high absorption of sun rays, so that the temperature effective upon the bimetallic or thermostatic strip 24 is somewhat in excess of the temperature effective upon the bimetallic strip 39 which is sheltered from direct sun radiation and is susceptible to air currents passing through the apertures 8.

The thermo-responsive element 32 responds'to general atmospheric temperature, which affects the whole structure, whereas the thermostatic element 24 is especially responsive to relatively large amounts of sun radiation, so that the differential movements of the contacts 29 and 3|,

due to the differential movements of the two thermo-responsive elements, afford a true response to sun radiation alone and control the electrical circuit inaccordance therewith. Thus, a valve as described herein is especially useful for automatically operatinga sign orfiasher such as shown in my co-pending application aboveidentified, in that it is effective to energize the sign byclosing the electrical circuit at night or when the sunlight ,or sun radiation is not sufiicient vto-give high visibility, whereas, during the daytime or when visibility is high, the electrical circuit is opened by the differentially responsive thermostatic mechanism and interrupts the electrical circuitto the indicator or flasher mechamam.

I claim:

1. A sun valve comprising a first thermostat, a second thermostat, contacts actuated by said thermostats and adapted to abut, a double-walled structure encompassing said first thermostat to confine a body of air thereabout, the outer wall of said structure being light permeable, and a casing open to the atmosphere surrounding said second thermostat.

2. A sun valve comprising a first thermostat, a second thermostat, contacts actuated by said thermostats and adapted to abut, a housing encompassing said first thermostat, a light permeable closure surrounding and spaced from said housing to confine air therebetween, and a casing open to the atmosphere surrounding said second thermostat.

3. A sun valve comprising a mounting, a spindle on said mounting, a contact arm fast on said spindle, a contact on said arm, a first thermostat for rotating said spindle with respect to said mounting, a second spindle on said mounting, a contact arm fast on said second spindle, acontact on said arm adaptedzto abut said first-named-com tact, a second'thermostat for rotating said second spindle with respect to said mounting, a chamber closed to the atmosphere and adapted to absorb a relatively large amount of sun rays encompassing said first thermostat, and a second chamber open to the atmosphere and adapted to absorb a relatively small amount of sun rays encompassing said second thermostat.

EDWIN H. PENDLETON. 

